Genome-Wide Identification of the CaMED Gene Family in Pepper (Capsicum annuum L.) and Functional Characterization of CaMED25a in the Heat Stress Response
Jun 2026· Horticulturae· Vol 12, pp. 772· 0 citations· 62 references
TL;DR
An integrated analysis of the pepper CaMED gene family is provided and the positive contribution of CaMED25a to heat stress tolerance is revealed.
Abstract
Pepper (Capsicum annuum L.) is an important horticultural crop whose growth, development, and yield formation are severely constrained by heat stress. The Mediator complex is a key transcriptional co-regulator in plants and plays important roles in developmental processes and stress responses. However, the MED gene family and its functions in heat stress responses remain largely unexplored in pepper. Using the chromosome-level reference genome of the cultivated pepper (Capsicum annuum var. annuum) cultivar Zhangshugang, a total of 49 CaMED genes were identified and classified into four conserved Mediator modules, namely the head, middle, tail, and kinase modules. Comprehensive bioinformatic analyses showed that CaMED genes are evolutionarily conserved across species, whereas differences in gene structure and sequence characteristics among family members may contribute to their functional diversification. Promoter analysis further showed that these genes contain abundant cis-acting elements related to light, phytohormone, and stress responses. Transcriptome analysis of the 49 identified CaMED genes showed distinct tissue-specific expression patterns, with many members showing preferential expression during early flower development and late placenta development. Furthermore, expression profiling of all CaMED genes using publicly available transcriptome datasets under 42 °C heat-stress conditions, followed by RT-qPCR validation of selected candidates, showed that CaMED25a displayed a relatively stable heat-responsive expression pattern. Virus-induced gene silencing of CaMED25a compromised heat tolerance in pepper plants under heat stress, as evidenced by increased H2O2 accumulation and significantly reduced expression of heat defense-related genes, including CaHSP18, CaHSP25.9, and CaHSP70.1. Taken together, this study provides an integrated analysis of the pepper CaMED gene family and reveals the positive contribution of CaMED25a to heat stress tolerance. These findings lay the groundwork for subsequent studies on CaMED gene function and the molecular regulation of high-temperature responses in pepper.
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Chen Qiu, Xinyue Long, Zhongshuai Gai et al.· International Journal of Mol...· 0 citations
The TIFY gene family comprises plant-specific transcriptional regulators central to jasmonic acid (JA) signaling and responses to biotic and abiotic stresses. Despite the economic importance of the banana (Musa spp.), the TIFY family remains largely uncharacterized in this crop. Here, we conducted a genome-wide identification and comprehensive analysis of the MaTIFY gene family in Musa acuminata. A total of 47 MaTIFY genes were identified, distributed across all 11 chromosomes. Phylogenetic analysis classified these into four subfamilies (TIFY, ZIZ/ZML, PPD, and JAZ), and conserved motif and domain analyses revealed a core TIFY domain architecture with subfamily-specific structural features. Gene Ontology (GO) enrichment and cis-acting regulatory element analyses suggested potential involvement in JA-mediated signaling, defense response, and hormone cross-talk. Expression profiling under drought, Fusarium oxysporum f. sp. cubense race 4 (Foc 4), and cold stress revealed distinct transcriptional responses, with MaTIFY5, MaTIFY16, MaTIFY20, MaTIFY26, and MaTIFY30 exhibiting enhanced induction in resistant cultivars compared to their susceptible counterparts. Functional characterization of MaTIFY20 confirmed its significant upregulation under drought stress and its ability to confer enhanced osmotic tolerance when heterologously expressed in yeast. These findings provide novel insights into the evolutionary dynamics and stress-responsive functions of banana TIFY genes and identify candidate targets for molecular breeding to improve abiotic and biotic stress resilience in banana.
Sheraz Ahmad, Huimin Song, Hangbo Cao et al.· International Journal of Mol...· 0 citations
This study elucidates the evolutionary conservation and functional diversity of the eggplant GATA family, providing valuable candidate genes for future functional research and stress-tolerant molecular breeding in eggplant.
Yang Huang, Li Jia, Kunyu Ma et al.· Horticulturae· 0 citations
The key marker genes and in silico interaction networks identified herein provide a robust resource for functional characterization and molecular breeding to improve stress resilience in zucchini.
Kevser Ceylan, M. Baloğlu, Y. Ceylan et al.· Plant growth regulation (Pri...· 0 citations
The SWEET (Sugars Will Eventually be Exported Transporter) family, a class of sugar transporters identified in recent years, plays important roles in plant growth and development. Increasing evidence suggests that SWEET genes are also involved in plant responses to abiotic stresses, including salt stress. However, the genome-wide composition and salt-responsive functions of SWEET genes in Elymus nutans Griseb. have not been systematically characterized to date. This study presents the first genome-wide identification of the SWEET gene family in E. nutans and functional characterization of EnSWEET15 in salt stress response, providing candidate genes and a theoretical basis for improving salt tolerance in this species. A total of 12 EnSWEET genes were identified from the E. nutans genome and were unevenly distributed across eight chromosomes. Phylogenetic analysis classified them into four subfamilies, and promoter analysis revealed abundant cis-elements related to hormone signaling and stress responses, suggesting roles in abiotic stress adaptation. Expression analysis showed that EnSWEET15 was significantly upregulated in both roots and leaves under salt stress. The full-length EnSWEET15 coding sequence (930 bp ORF) was cloned and functionally characterized. Heterologous overexpression in Arabidopsis thaliana indicated that EnSWEET15 enhances salt tolerance. Transgenic lines showed reduced reactive oxygen species (ROS) accumulation and increased activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), compared with wild-type plants under salt stress. Overall, this study identifies EnSWEET15 as a positive regulator of salt tolerance via modulating ROS homeostasis, providing novel insights into SWEET-mediated salt stress response in perennial forages and valuable genetic resources for salt-tolerant breeding of E. nutans.
Together, these findings provide a foundation for functional characterization and useful information for future research on the role of SlPHD family members in plant abiotic stress tolerance.
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